AT&T MERLIN LEGEND System Reference Manual page 428

Features
Hold
Inspect
Last Number Dial
Line Request
Messaging
Microphone Disable
Multi-Function Module
Music-on-Hold
Paging
Calls on hold for transfer are also timed so that the user or system operator
hears a reminder after the timer expires.
If a call is received on a personal line and is transferred to another user who
then puts the call on hold, another user who shares the personal line cannot
select the line button to pick up the call. If for some reason the person who
received the transfer and put the call on hold cannot return to the call, another
user must use the Line Pickup feature to pick up the call (for example, a system
operator can take a message and disconnect the caller).
If an MLX telephone user presses the Transfer button while Inspect is activated,
Inspect is canceled and the user is returned to the Home screen.
The Last Number Dial feature can be used to dial the outside number of the
telephone to which the call is being transferred.
Returning transferred calls cancel Line Request.
A non-display user who sends a message by using Leave Message while a
transfer is in progress cannot determine who received the message. For
example, if station A calls station B, and station B transfers the call to station C,
and if station A sends a message before the transfer is complete, station B
receives the message. If station A sends a message after station B completes
the transfer, station C receives the message, even if station C does not answer
and the call is ringing at station B as a transfer return.
If an inside call is transferred to a telephone with a posted message, only the
display telephone user who transfers the call sees the posted message. The
original caller does not see the posted message even after the transfer is
completed.
If a call is transferred to an extension programmed as a fax, the message
indication is not sent to the fax message-waiting receiver, regardless of the
amount of time programmed for the fax message-waiting threshold.
Calls can be transferred with a voice announcement to users whose
microphones are disabled, but the users must lift the handset to talk.
Calls cannot be transferred on an MFM since the system ignores the switchhook
flash.
An outside caller hears Music-on-Hold if programmed for Transfer Audible.
Calls cannot be transferred to paging groups or the loudspeaker paging
extension.
Transfer 2-379